1. Field of the Invention
The present invention relates to an x-y direction input device for moving a cursor on a screen in any direction.
2. Description of the Prior Art
An x-y direction input device for moving a cursor appearing on a display in any direction according to a magnitude of movement of an operating member has been proposed in the past.
FIG. 12 is a plan view showing an example of this kind of conventional x-y direction input device. FIG. 13 is an a cross-sectional view of the x-y direction input device taken along line 13--13 shown in FIG. 12.
A conventional x-y direction input device comprises, as shown in FIG. 12, a casing 1 having an aperture which is not shown, an operating member 2 resting on the casing 1 and movable relatively, an x-direction pattern 3 and a y-direction pattern 4 lying in the casing 1, a first moving member 6 holding a slider 5 which comes into contact with and slides along the x-direction pattern, a first guide means 7 guiding the moving member 6 in the x direction, a second moving member 9 holding a slider 8 which comes into contact with and slides along the y-direction pattern 4, and a second guide means 10 guiding the moving member 9 in the y direction. The operating member 2 comprises, as shown in FIG. 13, an axis 12 projecting upward from the aperture of the casing 1, a washer 13 fitted to the axis 12, and a knob 14 attached to the top end of the axis 12. The first moving member 6 has an elongated hole 6a that is elongated in the y direction and in which the axis 12 is inserted. The second moving member 9 is stacked on the moving member 6. The second moving member 9 also has an elongated hole 9a that is elongated in the x direction and in which the axis is inserted.
When the above conventional x-y direction input device is assembled, the axis 12 is inserted in the elongated holes 6a and 9a from under the first moving member 6, and then the washer 13 is fitted to the axis 12 in order to prevent the axis 12 from coming off. Thereafter, the knob 14 is attached to the top end of the axis 12. When the knob 14 is manually displaced in the x-y plane, the first moving member 6 and second moving member 9 are respectively moved in the x and y directions. The sliders 5 and 8 held by the moving members 6 and 9 detect the patterns 3 and 4 respectively. Thereby, a magnitude of movement of the knob 14 is detected. Thus, a cursor appearing on a display is moved to any position according to the magnitude of movement of the knob 14.
In the foregoing conventional x-y direction input device, when the knob 14 is manipulated, axial pressing force is applied to the axis 12. Therefore, the second moving member 9 is pressed down via the washer 13. This causes friction between the second moving member 9 and the first moving member 6 underlying the moving member 9. Consequently, these moving members 6 and 9 cannot move smoothly. Thus, the operability deteriorates.